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Chinese Journal of Antituberculosis ›› 2020, Vol. 42 ›› Issue (7): 718-724.doi: 10.3969/j.issn.1000-6621.2020.07.014

• Original Articles • Previous Articles     Next Articles

Analysis of the clinical isolation rate, population distribution and drug resistance of non-tuberculous mycobacteria in Anhui

BAO Xun-di, JIANG Yue, LIANG Suo, CHENG Hong-yan, XIA Guang-xiu, WANG Chao, YE Qian, WANG Shu, WANG Qing()   

  1. Laboratory of Anhui Chest Hospital (Anhui TB Institute), Hefei 230022, China
  • Received:2020-03-31 Online:2020-07-10 Published:2020-07-09
  • Contact: WANG Qing E-mail:ahtbcbs@163.com

Abstract:

Objective To analyze the clinical isolation rate, population distribution and drug resistance of non-tuberculous mycobacteria (NTM) in Anhui to provide a scientific basis for the prevention and treatment of NTM. Methods Using the stratified cluster sampling method, 42 investigation points were collected from 86 tuberculosis clinics in Anhui, and 3047 cases of smear-positive suspected pulmonary tuberculosis patients from September 15, 2015 to August 31, 2016 were continuously included. The 2652 positive strains with acid L-G medium were identified for strains (p-nitrobenzoic acid (PNB) culture and early secreted protein (MPB64) colloidal gold method) and gene sequencing (16S rRNA and hsp65 DNA sequencing), and then the NTM was clinically isolated. The distribution characteristics and drug resistance detection (microplate method) of strains in different populations were studied and analyzed. Results The 2652 culture-positive strains obtained 122 NTM strains through preliminary strain identification; and by genetic sequencing, 107 NTM clinical isolates (the coincidence rate was 87.70% (107/122), and the isolation rate was 4.03% (107/2652)), 12 strains of Mycobacterium tuberculosis, 1 strain of Nocardia, and 2 strains of contaminated bacteria were further obtained. Among them, a total of 6 dominant bacterial species were isolated from the 107 strains of NTM, mainly of Mycobacterium intracellulare (65.42% (70/107)) and Mycobacterium abscessus (25.23% (27/107)). The rate of NTM isolation in retreatment (9.26% (41/443)), female (6.32% (39/617)), 40 years old and above (5.11% (100/1956)), retirement (8.82% (12/136)) and farmers (4.38% (86/1965)), junior high school and below (4.43% (97/2189)) and family annual income <20000 CNY (4.98% (75/1506)) were significantly higher than those in the initial treatment (2.99% (66/2209)), male (3.34% (68/2035)), under 40 years old (1.01% (7/696)), workers (0.96% (1/104)), high school and above (2.16% (10/463)), and family annual income ≥20000 CNY (2.83% (27/955)) (χ 2 values were 37.434, 10.854, 36.387, 17.021,18.995 and 8.748, respectively; P values were 0.000, 0.001, 0.000, 0.002, 0.001 and 0.033, respectively). The drug susceptibility test results of 104 strains (excluding 1 strain of Mycobacterium intracellulare, 1 strain of Mycobacterium phlei, and 1 strain of Mycobacterium marseille which were failed to recover) showed that amikacin, rifabutin, clarithromycin and rifampicin were more sensitive (87.50% (91/104), 86.54% (90/104), 83.65% (87/104) and 75.00% (78/104), respectively), the resistance rates to imipenem/cilastatin sodium, cefoxitin, minocycline, doxycycline, etc. were higher (100.00% (104/104), 95.19% (99/104), 94.23% (98/104) and 93.27% (97/104), respectively). Conclusion The isolation rate of NTM in Anhui is lower, mainly in the retreatment, females, 40 years old and above, farmers, less educated and low income. The drug resistance rate is high, the laboratory identification and monitoring of NTM should be improved.

Key words: Mycobacteria, atypical, Bacteriological techniques, Microbial sensitivity tests, Drug resistance, bacterial, Epidemiologic studies, Outcome assessment (health care), Small-area analysis